But for industry-watchers interested in Kleiner’s portfolio, it’s worth pointing out that Doerr mentioned a new “stealth mode” lithium-ion battery maker. He says the unnamed startup “creates stable, durable lithium ion batteries with higher effective storage capacity” that can power electric vehicles “twice as far, and eventually three times as far, to over 100 miles before recharging.”

Doerr also gave a few clues on the company’s origins and future plans — supposedly the startup was found “outside the U.S.,” but is building manufacturing plants in the Midwest and will ship batteries at the end of the year. Doerr positioned the company as no less than an automotive breakthrough and said: “This technology could be a key driver for the electrification and revitalization of our automotive industry, helping us retain and create many jobs.”

Kleiner has openly invested in electric car companies, like Fisker Automotive, that will use lithium-ion batteries and in energy storage company EEStor (though Kleiner Perkins doesn’t list the company on its web site). EEStor says its energy storage technology for vehicles can provide 10 times the energy of lead-acid batteries at one-tenth the weight and half the price, and move a car 400 kilometers after a five-minute charge. But EEStor isn’t working on lithium-ion batteries that we know of.

Kleiner has previously invested in deals where Khosla Ventures (founded by former Kleiner partner Vinod Khosla) has done early seed stage funding. That firm has backed Sakti3, an Ann Arbor, Mich.-based company developing a next-generation lithium-ion battery for electric vehicles. According to this Detroit Free Press article (one of the only detailed ones we’ve seen on the company) Sakti3 will build factories to turn Michigan “into a major producer of lithium-ion batteries for electric vehicles.” But also, according to the article, Sakti3’s technology is based on research conducted at University of Michigan — not overseas.

If anyone has ideas on Kleiner’s secretive lithium ion battery company, add them in the comments or email us.